Substrate stage mechanism and substrate processing apparatus

ABSTRACT

A substrate stage mechanism ( 10 ) configured to place a substrate (W) thereon inside a process container of a substrate processing apparatus ( 100 ) and having a substrate heating function for heating the substrate (W) includes a substrate table ( 11 ) including a base body ( 11   a ) configured to place the substrate (W) thereon and a heating element ( 13 ) provided to the base body ( 11   a ) and configured to heat the substrate (W); a support member ( 12 ) having an upper end connected to the substrate table ( 11 ) and a lower end attached to the process container; and a heating device ( 17 ) configured to heat the support member ( 12 ).

TECHNICAL FIELD

The present invention relates to a substrate stage mechanism including asubstrate heating function for heating a substrate placed thereon, suchas a semiconductor substrate, inside a process container of a substrateprocessing apparatus, such as a film forming apparatus. The presentinvention further relates to a substrate processing apparatus thatemploys the substrate stage mechanism.

BACKGROUND ART

In the sequence of manufacturing semiconductor devices, a vacuumprocess, such as a CVD film forming process or plasma etching process,is performed on a target substrate or semiconductor wafer. During such aprocess, the target substrate or semiconductor wafer is heated by asubstrate table serving as a heater, so that the semiconductor wafer isset at a predetermined temperature.

As a heater of this kind, a stainless heater is conventionally used,but, in recent years, there has been proposed use of a ceramic heater,which is corrosion-resistant relative to halogen family gases used inthe processes described above and has a high thermal efficiency (PatentDocument 1 and so forth). The ceramic heater includes a heating elementmade of a refractory metal and embedded in a base body made of acompacted ceramic sintered body, such as AlN, which serves as a tablefor placing a target substrate thereon.

Where a substrate table comprising a ceramic heater is used in asubstrate processing apparatus, the bottom of the substrate table isconnected to one end of a support member formed of a ceramic cylinder,while the other end of the support member is connected to the bottom ofa chamber. Electric feed lines for feeding electricity to the heatingelement are disposed in the support member and connected to terminals ofthe heating element. A power supply is externally disposed to feedelectricity through the electric feed lines and electric feed terminalsto the heating element.

A substrate table comprising a ceramic heater includes electric feedterminals near the junction to the support member, and thus the heatingelement inevitably has a lower density at this portion. Further, at thejunction of the substrate table to the support member, heat can bedischarged by thermal conduction through the support member.Consequently, cool spots (portions having a lower temperature than theportions around them) are generated around the junction of the substratetable, and thermal stress concentration occurs at these portions andbrings about cracks near the junction with a considerable frequency. Ifthe temperature around the junction is increased by the heating elementembedded in the substrate table to solve this problem, the temperaturedistribution on the substrate mount face of the substrate table is lessoptimized to the process.

Patent Documents 2 and 3 disclose techniques for relaxing the thermalstress at the junction thereby preventing crack generation, but thesetechniques require complicate shaping mainly for the support member.Further, in recent years, along with an increase in the size ofsemiconductor wafers, the size of substrate tables have also increased.This trend makes it less effective to rely on the shape of the supportmember in relaxing the thermal stress, and thus makes it difficult toreliably prevent crack generation.

[Patent Document 1]

Jpn. Pat. Appln. KOKAI Publication No. 7-272834

[Patent Document 2]

Jpn. Pat. Appln. KOKAI Publication No. 2001-250858

[Patent Document 3]

Jpn. Pat. Appln. KOKAI Publication No. 2003-289024

DISCLOSURE OF INVENTION

An object of the present invention is to provide a substrate stagemechanism, which can reliably prevent crack generation at a positionbetween a substrate table and a support member while maintaining asuitable temperature distribution on the substrate mount face of thesubstrate table.

Another object of the present invention is to provide a substrateprocessing apparatus that employs the substrate stage mechanism.

According to a first aspect of the present invention, there is provideda substrate stage mechanism configured to place a substrate thereoninside a process container of a substrate processing apparatus andhaving a substrate heating function for heating the substrate, thesubstrate stage mechanism comprising: a substrate table including a basebody configured to place the substrate thereon and a heating elementprovided to the base body and configured to heat the substrate; asupport member having one end connected to the substrate table andanother end attached to the process container; and a heating deviceconfigured to heat the support member.

According to a second aspect of the present invention, there is provideda substrate processing apparatus comprising: a process containerconfigured to accommodate a substrate and hold a vacuum pressuretherein; a substrate stage mechanism disposed inside the processcontainer and configured to place the substrate thereon; and a processmechanism configured to perform a predetermined process on the substrateinside the process container, wherein the substrate stage mechanismcomprises a substrate table including a base body configured to placethe substrate thereon and a heating element provided to the base bodyand configured to heat the substrate, a support member having one endconnected to the substrate table and another end attached to the processcontainer, and a heating device configured to heat the support member.

In either of the first aspect and the second aspect, the heating devicemay be configured to heat the support member by radiation. The heatingdevice may be configured to heat an area near a junction between thesubstrate table and the support member. The support member may betubular, and the heating device may be disposed inside the supportmember.

The heating device may comprise a heater including a carbon wire servingas a heating element and sealed inside a quartz glass tube. The heatingdevice may include a halogen lamp. The heating device may be configuredto heat the support member by thermal conduction. In this case, theheating device may comprise a resistance heating heater.

The support member may be connected to a central portion of thesubstrate table. The substrate stage mechanism may further comprise acontrol device configured to control the heating device to heat an areanear the junction in accordance with temperature of the substrate table.

According to the present invention, the heating device is disposed toheat the support member that supports the substrate table, so that thesupport member is heated by the heating device while the substrate isheated by the substrate table, to prevent heat from being dischargedfrom the substrate table to the support member. Consequently, thejunction between the substrate table and the support member can be freefrom thermal stress, thereby reliably preventing crack generation at thejunction. Further, the heating device for heating and preventing heatdischarge from the substrate table is independent of the heating elementfor heating the substrate. Consequently, the heating of the heatingelement can be optimized to maintain a suitable temperature distributionon the mount face of the substrate table.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 This is a sectional view schematically showing a CVD film formingapparatus including a wafer stage mechanism according to an embodimentof the present invention.

FIG. 2 This is an enlarged sectional view showing the wafer stagemechanism according to the embodiment of the present invention, in anenlarged state.

FIG. 3 This is a sectional view showing the structure of a carbon heaterused as a heating device of a support member in the wafer stagemechanism according to the embodiment of the present invention.

FIG. 4 This is a plan view showing the carbon heater.

FIG. 5 This is a block diagram showing an example of a control system ofa heating element for heating a wafer table and a carbon heater forheating a support member in the wafer stage mechanism according to theembodiment of the present invention.

FIG. 6 This is a view for explaining a state where a conventional waferstage mechanism is used.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will now be described withreference to the accompanying drawings.

In this embodiment, an explanation will be given of a case where asubstrate stage mechanism according to the present invention is appliedto a CVD film forming apparatus.

FIG. 1 is a sectional view schematically showing a CVD film formingapparatus including a wafer stage mechanism according to an embodimentof the present invention. The CVD film forming apparatus 100 includes anessentially cylindrical airtight chamber 2 and an exhaust chamber 3projected downward from the bottom wall 2 b of the chamber 2, such thatthe chamber 2 and exhaust chamber 3 form an integral process container.The chamber 2 is provided with a wafer stage mechanism 10 disposedtherein for supporting and heating a target object or semiconductorwafer (which will be simply referred to as wafer) W in a horizontalstate. The wafer stage mechanism 10 includes a wafer table 11 having awafer mount face and a heating element embedded therein as describedlater, and a cylindrical support member 12 extending upward from thebottom of the exhaust chamber 3 of the process container and supportingthe center of the wafer table 11. A power supply 5 for feedingelectricity to the heating element of the wafer table 11 and so forth isdisposed outside the chamber 2, so that electricity is supplied througha connector casing 20 to the heating element and so forth. The powersupply 5 is connected to a controller 7 configured to control the amountof electricity supplied from the power supply 5, so that the temperatureof the wafer table 11 and so forth is controlled. This control systemwill be explained in detail later. Further, the wafer table 11 isprovided with a guide ring 6 disposed on the edge to guide the wafer W.

A showerhead 30 is disposed on the ceiling wall 2 a of the chamber 2.The showerhead 30 is formed of an upper block body 30 a, a middle blockbody 30 b, and a lower block body 30 c. A first gas feed port 31 and asecond gas feed port 32 are formed in the upper surface of the upperblock body 30 a. On the other hand, gas delivery holes 33 and 34 arealternately formed in the lower block body 30 c.

The first and second gas feed ports 31 and 32 are respectively connectedto gas supply lines 35 and 36 extending from a gas supply mechanism 40.For example, the gas supply mechanism 40 is configured to supply TiCl₄gas and NH₃ gas respectively through the gas supply lines 35 and 36 andthe first gas feed port 31 and second gas feed port 32 into theshowerhead 30. Then, these gases are independently supplied through gaspassages formed in the block bodies, and then delivered respectivelyfrom the gas delivery holes 33 and 34. In other words, a post mix typeis adopted such that the gas introduced from the first gas feed port 31and the gas introduced from second gas feed port 32 are not mixed insidethe showerhead 30, but delivered from different gas delivery holes 33and 34 and then mixed.

A circular opening 4 is formed at the center of the bottom wall 2 b ofthe chamber 2, and the exhaust chamber 3 is disposed to cover theopening 4 and project downward. The sidewall of the exhaust chamber 3 isconnected to an exhaust unit 52 through an exhaust line 51. The exhaustunit 52 can be operated to decrease the inner pressure of the chamber 2to a predetermined vacuum level.

The wafer table 11 is provided with three wafer support pins 53 (onlytwo of them are shown in FIG. 1) that can project and retreat relativeto the surface of the wafer table 11 to support the wafer W and move itup and down. The wafer support pins 53 are fixed to a support plate 54and are moved up and down along with the support plate 54 by a drivingmechanism 55, such as an air cylinder.

The chamber 2 has a transfer port 56 formed in the sidewall and providedwith a gate valve 57 for opening/closing the transfer port 56, so thatthe wafer W is transferred between the chamber 2 and a transfer chamber(not shown) held in a vacuum state, through the transfer port 56.

Next, a detailed explanation will be given of the wafer stage mechanism10, with reference to the enlarged sectional view shown in FIG. 2.

As described above, the wafer stage mechanism 10 includes the wafertable 11 and the cylindrical support member 12 that supports the wafertable 11. The wafer table 11 is structured as a ceramic heater, whichincludes a base body 11 a made of a ceramic material, such as AlN,Al₂O₃, SiC, or SiO₂, and a heating element 13 embedded in the base body11 a and made of a refractory metal, such as W, Mo, V, Cr, Mn, Nb, orTa, or a compound thereof. The heating element 13 is formed of twozones, and these two zone parts of the heating element 13 are connectedto electric feed terminals 14 for feeding electricity, at the centralportion of the wafer table 11. Each of the two zone parts of the heatingelement 13 is provided with two terminals 14, but FIG. 2 shows only oneterminal 14 for each of the two zone parts of the heating element 13,i.e., shows totally only two terminals 14, for the sake of convenience.

The support member 12 is also made of a ceramic material, such as AlN,Al₂O₃, SiC, or SiO₂, as in the wafer table 11, and is connected to thecentral portion of the bottom of the wafer table 11. The support member12 envelops four electric feed rods 15 (only two of them are shown inFIG. 2) extending in the vertical direction. The upper ends of theelectric feed rods 15 are connected to the electric feed terminals 14,and the lower ends thereof are extended into the connector casing 20,which is attached to the bottom of the support member 12 and isprojected downward from the exhaust chamber 3. The electric feed rods 15are made of a heat-resistant metal material, such as an Ni alloy.

The support member 12 further envelops two thermo couples 16 a and 16 bextending in the vertical direction. The upper end of the thermo couple16 a is embedded in the wafer table 11, and the upper end of the thermocouple 16 b is disposed at the upper end of the support member 12. Thelower ends of the thermo couples 16 a and 16 b are extended into theconnector casing 20. The thermo couple 16 a is configured to detect thetemperature of the wafer table 11, and is used for feedback control ofthe temperature of the wafer. The thermo couple 16 b is used for controlof the temperature of a carbon heater, as described later.

The support member 12 further envelops a carbon heater 17 serving as aheating device for heating the support member 12. The carbon heater 17includes two (see FIG. 4) electric feed portions 18 extending in thevertical direction inside the support member 12 and a heating portion 19connected to the distal ends of the electric feed portions 18. As shownin FIG. 3, each of the electric feed portions 18 includes a quartz glasstube 41 and an electric feed rod 42 extending in the tube 41. Theheating portion 19 includes a quartz glass tube 43 having a diametersmaller than that of the quartz glass tube 41 of the electric feedportions 18 and a carbon wire 44 extending in the tube 43 and serving asa heating element connected to the electric feed lines. As shown in FIG.2 and the plan view of FIG. 4, the heating portion 19 is bent up anddown and circulated inside an upper side of the support member 12 so asnot to interfere with the electric feed rods 15 and thermo couples 16 aand 16 b. With this arrangement, an area near the junction between thewafer table 11 and support member 12 can be effectively and uniformlyheated. The two electric feed portions 18 are interlocked with eachother by a support rod 18 a. The heating portion 19 is supported by asupport rod 19 a extending across the diameter in parallel with thesupport rod 18 a. The support rods 18 a and 19 a serve to prevent thecarbon heater 17 from being deformed.

A flange-like bottom lid 21 made of an insulator is attached to thebottom of the support member 12 by an attachment 21 a and screws 21 b.The bottom lid 21 has vertical holes for inserting the electric feedrods 15, thermo couples 16 a and 16 b, and carbon heater 17. Theconnector casing 20 is cylindrical and has a flange 20 a formed at theupper end. The flange 20 a is sandwiched by the bottom lid 21 and thebottom wall of the exhaust chamber 3. A ring seal member 23 a isdisposed between the flange 20 a and the bottom wall of the exhaustchamber 3 to seal this portion airtight. Two ring seal members 23 b aredisposed between the flange 20 a and the bottom lid 21 to seal thisportion airtight. Inside the connector casing 20, the electric feed rods15 and carbon heater 17 are connected to electric feed lines 45extending from the power supply 5, and the thermo couples 16 a and 16 bare connected to wiring lines 46 extending from the controller 7.

Next, an explanation will be given of a control system for the entirefilm forming apparatus 100.

The respective components of the film forming apparatus 100 areconnected to and controlled by a process controller 60. The processcontroller 60 is connected to a user interface 61 including, e.g. akeyboard and a display, wherein the keyboard is used for a processoperator to input commands for operating the film forming apparatus 100,and the display is used for showing visualized images of the operationalstatus of the plasma processing apparatus 100.

Further, the process controller 60 is connected to a storage section 62that stores control programs for the process controller 60 to controlthe film forming apparatus 100 so as to perform various processes, andprograms or recipes for respective components of the film formingapparatus 100 to perform processes in accordance with processconditions. Recipes may be stored in a hard disk or semiconductormemory, or stored in a portable storage medium, such as a CDROM or DVD,to be attached to a predetermined position in the storage section 62.Further, recipes may be transmitted from another apparatus through,e.g., a dedicated line, as needed.

A required recipe is retrieved from the storage section 62 and executedby the process controller 60 in accordance with an instruction or thelike through the user interface 61, as needed. Consequently, the filmforming apparatus 100 can perform a predetermined process under thecontrol of the process controller 60.

Next, an explanation will be given of a control system for the heatingelement 13 and carbon heater 17, with reference to FIG. 5. Thecontroller 7 includes a first control portion 7 a for controlling thetemperature of the table 11, and a second control portion 7 b forcontrolling the heating temperature of the carbon heater 17. The powersupply 5 includes a first power supply portion 5 a for feedingelectricity to the heating element 13, and a second power supply portion5 b for feeding electricity to the carbon heater 17. The first controlportion 7 a and second control portion 7 b are controlled by a processcontroller 60 serving as a host controller. The first control portion 7a is configured to receive detection signals from the thermo couple 16 aand to transmit instructions to the first power supply portion 5 a inaccordance with the detection signals and instructions from the processcontroller 60, thereby controlling electric feed to the heating element13. The second control portion 7 b is configured to receive detectionsignals from the thermo couple 16 b and to transmit instructions to thesecond power supply portion 5 b in accordance with the detection signalsand instructions from the process controller 60, thereby controllingelectric feed to the carbon heater 17. The process controller 60 isconfigured to control the first control portion 7 a and second controlportion 7 b, so that the carbon heater 17 heats an area near thejunction between the wafer table 11 and support member 12 in accordancewith the temperature of the wafer table 11.

The carbon heater 17 is conceived to thermally insulate the wafer table11 and prevent cool spots from being generated, as described later, sothe carbon heater 17 does not require precise control unlike the wafertable 11. Further, it is necessary to prevent the members inserted inthe support member 12 from interfering with each other, as far aspossible. In light of these matters, the temperature of the carbonheater 17 may be controlled by open loop control based on voltage,without use of the thermo couple 16 b.

In the film forming apparatus 100 having the structure described above,at first, electricity is supplied to the heating element 13 embedded inthe wafer table 11 from the first power supply portion 5 a of the powersupply 5, so that the wafer table 11 is heated to, e.g., about 700° C.Further, the interior of the process container 1 is exhausted by theexhaust unit 52 at full throttle. In this state, the gate valve 57 isopened, and a wafer W is transferred from the transfer chamber (notshown) in a vacuum state through the transfer port 56 into the chamber2. After the wafer W is placed on the top of the wafer table 11, thegate valve 57 is closed. Then, film formation gases are supplied atpredetermined flow rates from the gas supply mechanism 40 through thegas supply lines 35 and 36 into the showerhead 30. These gases aredelivered from the showerhead 30 into the chamber 2, and caused to reactwith each other on the surface of the wafer W, thereby forming apredetermined film on the wafer W. For example, where TiCl₄ gas and NH₃gas are used as the film formation gases, TiCl₄ gas and NH₃ gas reactwith each other on the surface of the wafer W on the wafer table 11, sothat a TiN film is formed by thermal CVD.

Conventionally, during such a film forming process, no heating isapplied to the support member 12, and the following problems are therebycaused. Specifically, the upper end of the support member 12 is directlyconnected to the wafer table 11, and the lower end of the support member12 is connected to the connector casing 20 having a bottom located onthe atmospheric side, so heat is discharged by thermal conduction fromthe wafer table 11 through the support member 12 to the atmosphericside. Further, the support member 12 is connected to the central portionof the wafer table 11, at which electric feed terminals are present, sothe density of the heating element cannot be increased at the centralportion. Consequently, as shown in FIG. 6, cool spots C are generatedaround the junction between the wafer table 11 and support member 12,and thermal stress concentration occurs at these portions and bringsabout cracks near the junction with a considerable frequency. If theheating at the junction is enhanced by the heating element 13 to solvethis problem, the central portion of a wafer, where the temperaturetends to be higher, is enhanced, so the temperature distribution on themount face of the wafer table 11 is less optimized.

On the other hand, according to the embodiment, the carbon heater 17 isdisposed in the support member 12 as a heating device for heating thesupport member 12, so as to heat an area near the junction between thewafer table 11 and support member 12. Consequently, heat is preventedfrom being discharged from the wafer table 11 through the support member12, so that no cool spots are formed. Further, the carbon heater 17 isconfigured to heat the support member 12 to remove cool spotsindependently of the heating of the wafer table 11. Consequently, thetemperature of the wafer table 11 can be controlled by the heatingelement 13 to be optimum to the process.

The carbon heater 17 is disposed inside the support member 12 to heat anarea near the junction between the wafer table 11 and support member 12by radiant heat. In this case, the carbon heater 17 can be incorporatedin the existing apparatus without entailing any change therein, so thisincorporation can be easily realized. In order to remove the cool spots,a heater may be embedded in the support member 12. However, thiscountermeasure entails difficulty in manufacturing the support member 12because the heater needs to be embedded in a thin plate portion.Further, thermal stress concentration may occur at a portion where thethickness is changed, and generate a crack therefrom. Accordingly, it isadvantageous to adopt the structure according to the embodiment, inwhich the carbon heater 17 is disposed inside the support member 12 toheat the support member 12 by radiant heat.

In the carbon heater 17 used as a heating device, the quartz glass tube41, quartz glass tube 43, and carbon wire 44 have high purity andcontain essentially no impurity, so they can hardly generatecontaminants, such as metal contaminants, as well as organiccontaminants. Further, quartz glass making the outer shell of the carbonheater 17 can be easily processed so as to form such a shape that can bedisposed inside the narrow space of the support member 12 withoutinterference with the members inserted in the support member 12, and canrealize uniform heating.

The heating temperature of the carbon heater 17 is not necessarilyrequired to be the same as the temperature of the wafer table 11. Evenwhere the heater 17 is set to perform heating to some extent, thethermal conduction from the wafer table 11 to the support member 12 isdecreased, so that the thermal stress due to cool spots is suppressed.For example, where the temperature of the wafer table 11 is controlledat 700° C., a set temperature of 500° C. used in the carbon heater 17 issufficiently effective. However, in order to enhance this effect, thetemperature of the carbon heater 17 is preferably controlled such thatthe temperature near the junction becomes the same as the temperature ofthe wafer table 11.

The present invention is not limited to the embodiment described above,and it may be modified in various manners. For example, in theembodiment described above, the carbon heater serving as a heatingdevice for the support member is disposed in a state in which it is bentup and down and circulated. In this respect, the carbon heater may bedisposed in another state, such as a spiral state, as long as it canheat the area in need with predetermined uniformity.

The carbon heater is used as a heating device because it can be easilyshaped for setting inside the support member. However, another heatingdevice may be used, as long as it can be disposed inside the supportmember 12. Particularly, a halogen lamp is preferably usable, because itcan perform heating at about 700° C. by radiant heat, involve fewimpurity, and provide a good heating efficiency. Where a halogen lamp isused, it is possible to use a structure essentially the same as that ofthe carbon heater shown in FIG. 3 including the quartz glass tube 43 andthe carbon wire disposed therein as a heating element. Specifically, astructure for this modification may include a quartz glass tube and aheating element disposed therein, such as a tungsten filament, whereinthe filament may be bent in the shape shown in FIG. 2 or in anotherarbitrary shape.

As the type of heating device, heating by thermal conduction may be usedin place of the heating by radiant heat described above. A heatingdevice of the type that provides heating by thermal conduction isexemplified by a resistance heating heater. Where a resistance heatingheater is used, it is possible to use a structure essentially the sameas that shown in FIG. 3, which includes a quartz tube and a heatingelement disposed therein. In this case, the heating element may beformed of a resistance heating element made of a refractory metal, suchas tungsten, and bent in the shape shown in FIG. 2 or in anotherarbitrary shape. In place of a quartz tube, a tube made of a metal, suchas Ni, stainless steel, or HASTELLOY™, may be used. As a resistanceheating heater, a heating element of a refractory metal wire bent in anarbitrary shape may be used.

In the embodiment described above, a heating device for heating thesupport member is disposed inside the support member. In this respect, aheating device for this purpose may be disposed outside the supportmember if the process atmosphere is less corrosive. Alternatively,depending on the shape of the support member, a heating device for thispurpose may be embedded in the support member. However, a heating devicefor this purpose is preferably disposed inside the support member as inthe embodiment, because setting thereof is easy and consideration forcorrosion is not required.

In the embodiment described above, the support member is connected tothe wafer table essentially at the center. Alternatively, for example, aplurality of support members may be connected to the peripheral portionof the wafer table, so that the same effect is attained.

In the embodiment described above, the substrate stage mechanismaccording to the present invention is applied to a CVD film formingapparatus. However, the substrate stage mechanism is applicable to anyprocessing apparatus that heats and processes a substrate. The targetsubstrate is not limited to a semiconductor wafer, and it may be anothersubstrate, such as that of a flat panel display, a representative ofwhich is a liquid crystal display.

INDUSTRIAL APPLICABILITY

The present invention is widely usable for heating processes, such asthermal CVD, performed on a substrate by use of a substrate stagemechanism, which includes a substrate table configured to place thesubstrate thereon inside a chamber and supported by a support member.

1. A substrate stage mechanism configured to place a substrate thereoninside a process container of a substrate processing apparatus andhaving a substrate heating function for heating the substrate, thesubstrate stage mechanism comprising: a substrate table including a basebody configured to place the substrate thereon and a heating elementprovided to the base body and configured to heat the substrate; asupport member having one end connected to the substrate table andanother end attached to the process container; and a heating deviceconfigured to heat the support member.
 2. The substrate stage mechanismaccording to claim 1, wherein the heating device is configured to heatthe support member by radiation.
 3. The substrate stage mechanismaccording to claim 1, wherein the heating device is configured to heatan area near a junction between the substrate table and the supportmember.
 4. The substrate stage mechanism according to claim 1, whereinthe support member is tubular, and the heating device is disposed insidethe support member.
 5. The substrate stage mechanism according to claim2, wherein the heating device comprises a heater including a carbon wireserving as a heating element and sealed inside a quartz glass tube. 6.The substrate stage mechanism according to claim 2, wherein the heatingdevice includes a halogen lamp.
 7. The substrate stage mechanismaccording to claim 1, wherein the heating device is configured to heatthe support member by thermal conduction.
 8. The substrate stagemechanism according to claim 7, wherein the heating device comprises aresistance heating heater.
 9. The substrate stage mechanism according toclaim 1, wherein the support member is connected to a central portion ofthe substrate table.
 10. The substrate stage mechanism according toclaim 3, wherein the substrate stage mechanism further comprises acontrol device configured to control the heating device to heat the areanear the junction in accordance with temperature of the substrate table.11. A substrate processing apparatus comprising: a process containerconfigured to accommodate a substrate and hold a vacuum pressuretherein; a substrate stage mechanism disposed inside the processcontainer and configured to place the substrate thereon; and a processmechanism configured to perform a predetermined process on the substrateinside the process container, wherein the substrate stage mechanismcomprises a substrate table including a base body configured to placethe substrate thereon and a heating element provided to the base bodyand configured to heat the substrate, a support member having one endconnected to the substrate table and another end attached to the processcontainer, and a heating device configured to heat the support member.12. The substrate processing apparatus according to claim 11, whereinthe heating device of the substrate stage mechanism is configured toheat the support member by radiation.
 13. The substrate processingapparatus according to claim 11, wherein the heating device of thesubstrate stage mechanism is configured to heat an area near a junctionbetween the substrate table and the support member.
 14. The substrateprocessing apparatus according to claim 11, wherein the support memberof the substrate stage mechanism is tubular, and the heating device isdisposed inside the support member.
 15. The substrate processingapparatus according to claim 12, wherein the heating device of thesubstrate stage mechanism comprises a heater including a carbon wireserving as a heating element and sealed inside a quartz glass tube. 16.The substrate processing apparatus according to claim 12, wherein theheating device of the substrate stage mechanism includes a halogen lamp.17. The substrate processing apparatus according to claim 11, whereinthe heating device of the substrate stage mechanism is configured toheat the support member by thermal conduction.
 18. The substrateprocessing apparatus according to claim 17, wherein the heating deviceof the substrate stage mechanism comprises a resistance heating heater.19. The substrate processing apparatus according to claim 11, whereinthe support member of the substrate stage mechanism is connected to acentral portion of the substrate table.
 20. The substrate processingapparatus according to claim 13, wherein the substrate stage mechanismfurther comprises a control device configured to control the heatingdevice of the substrate stage mechanism to heat the area near thejunction in accordance with temperature of the substrate table.